Splint for a joint connection and methods for production of such a splint

ABSTRACT

The invention relates to a splint for a joint connecting two parts of a human body or of an animal, such as the ankle, knee or elbow for example, comprising at least one rigid shell ( 1,2 ), globally concave, for positioning around the joint in order to support said joint. The splint comprises, on the internal face thereof, in other words the concave face, a chamber ( 3,4 ) made from a flexible plastic material which may be placed under pressure by any suitable means, and positioned on the internal face of the shell ( 1,2 ) to provide a supportive cushion between said shell ( 1, 2 ) and the joint and covering at least a part of the internal face of the shell ( 1,2 ). The splint comprises means ( 6 ) for holding said shell ( 1,2 ) in position about the joint, characterized in that the shell ( 1,2 ) is made from a single element comprising at least one flexible zone ( 7, 8;12, 13 ) made from a styrene ethylene butylene styrene block copolymer (SEBS), chemically bonded to the rigid part of the shell ( 1,2 ) to avoid any injury to the oedematic tissue which appears after a sprain or strain of said joint.

This invention relates to a splint for a joint between two members of ahuman or animal body, for example such as the ankle, knee or elbow,composed of at least two rigid and globally concave shells that can bepositioned on each side of the joint, resting on the said joint,comprising means of avoiding an injury to the oedematous tissue thatdeveloped subsequent to a severe or minor sprain of the said joint.

In the field of traumatology, particularly in sport, ankle orthoses,commonly called splints are well known to avoid foot eversion andinversion movements while allowing normal bending of the foot, either toprevent a severe or minor sprain of the ankle, for example whilepracticing a sport, or to encourage resorption of an oedema resultingfrom a severe sprain and located around the ankle. These splints areusually composed of two rigid and globally concave shells that can bepositioned on each side of the ankle, applying pressure on the saidankle, and comprising a chamber made of a flexible plastic material thatcan be pressurised by any appropriate means, on each of their innerfaces, in other words on their concave faces. These chambers are placedon the inner face of each shell to supply a supporting cushion betweeneach shell and the ankle, and they cover at least part of the inner faceof each shell, such that during every step, these chambers compress theoedematous tissues creating a massage effect that contributes to a fastdisappearance of oedemas. Furthermore, the splint comprises means ofholding the said shells in position on each side of the joint composedof fabric strap surrounding the said shells of the splint.

This type of splint is described in European patent EP 0 252 121deposited by the AIRCAST company, and concerning an ankle splint. Thissplint is composed of an outer envelope comprising two rigid and concaveshells that can be positioned on each side of the ankle, and a base thatis also rigid and can be positioned under the heel. The base comprisestwo tabs made from a fabric strap extending on each side of the saidbase and comprising loops on their outer faces, on each of theircorresponding ends, capable of cooperating with “velcro” (registeredtrademark) type hooks moulded in the inner surface of each shell justabove a globally rectangular horizontal slot located at the lower end ofeach shell, each tab being inserted in the slot in its correspondingshell from the outside of the shell towards the inside. The splint alsocomprises a first and a second chamber that can be pressurized toprovide a support cushion between each shell and the ankle, the secondchamber extending along the inner part of the first chamber close to thebase. Furthermore, the splint comprises means of holding the shells incontact with the leg such that the pressure applied by the secondchamber in contact with the ankle is relatively higher than the pressureapplied on the leg by the part of the first chamber extending above thesecond chamber.

This type of splint has the disadvantage of having rigid edges that canbear on the oedematous tissue of the ankle causing inconvenience andpain due to the pressure applied by the rigid edges of the shells.Furthermore, the tabs on the base of the splint are fixed to the innerwalls of the shells, therefore it is necessary to remove the entiresplint to access the said tabs and adjust the height of the shells withrespect to the base correctly, with the result that the splint is badlypositioned most of the time, which is very uncomfortable for personswearing these splints.

In order to overcome these disadvantages, splints have been conceivedcomposed of a central rigid shell provided with linings along itslongitudinal edges made from a resilient material; for example, this isthe case of American patent U.S. Pat. No. 5,716,335. These linings aremade of rubber or a similar material and are glued onto the longitudinaledges of the rigid shell that includes grooves to enable mechanicalcoupling of linings with the central rigid shell made of high densitypolyethylene (HDPE), nylon or nylon with a glass filler marketed by theDUPONT Company (registered trademark).

The linings of these splints have the disadvantage that they can detach,or even tear off in the case of prolonged and repeated use of thesesplints, thus making them completely inefficient. Furthermore, frictionbetween the rubber and the skin of a patient wearing the splint barefootare particularly uncomfortable and can cause burns.

Therefore one of the purposes of this invention is to overcome thisdisadvantage by proposing a splint for a joint between two members of ahuman or animal body, for example such as the ankle, with a simpledesign and that can avoid an injury to the oedematous tissue thatdeveloped subsequent to a severe or minor sprain of the said joint.

According to the invention, this is achieved by making a splint for ajoint between two members of a human or animal body, for example such asthe ankle, knee or elbow, composed of at least one rigid and globallyconcave shell that can be positioned around the joint, bearing on thesaid joint, and comprising a chamber made of a flexible plastic materialthat can be pressurized by any appropriate means, placed on the innerface of the shell, in other words the concave face, to provide a supportcushion between the said shell and the joint, and covering at least partof the inner face of the shell, the said splint comprising means ofholding the said shell in position around the joint; this splint isremarkable in that the shell is composed of a single element comprisingat least one flexible area made from a styrene ethylene butylene styrene(SEBS) block copolymer chemically bonded to the rigid part of the shellto avoid any injury to the oedematous tissue that developed subsequentto a severe or minor sprain of the said joint.

According to one essential characteristic of the splint according to theinvention, the shell is rigid in the central part and flexible on eachof its longitudinal edges.

It is quite obvious that since the edges of the shells are flexible,they apply a lower pressure on the oedematous tissue resulting from asevere or minor sprain during bending of the foot, thus facilitatingfast resorption of the oedema. Moreover, apart from the fact that SEBSis a pleasant material to touch, it improves the feeling of comfort fora user wearing the splint barefoot, the shell being made in a singlepart, in other words from a single mould, the flexible part of the shelldoes not tear off unlike devices according to prior art.

Another purpose of the invention relates to a method of manufacturingthe shell(s) of a splint for a joint connecting two members of a humanor similar body, for example such as the ankle, knee or elbow, composedof at least one rigid and globally concave shell, that can be positionedaround the joint and bearing on the said joint.

This method consists of inserting a hot liquid synthetic material thatsolidifies as it cools in a mould defining the shape of the shell to beobtained, and then inserting a flexible material into the said mould inat least one area of the said mould.

According to one variant embodiment of the method according to theinvention, the flexible material is added into the synthetic material.

Other advantages and characteristics will become clearer after readingthe following description given as a non-limitative example, of a splintaccording to the invention with reference to the appended figures,wherein:

FIG. 1 is an exploded perspective view of a splint for a left ankle,according to the invention,

FIG. 2 is a side view of the outer shell of the splint for an ankle,according to the invention as shown in FIG. 1,

FIG. 3 is a side view of the inner shell of the splint for an ankleaccording to the invention as shown in FIG. 1,

FIG. 4 is a front sectional view of the ankle splint in position on theankle of a person,

FIG. 5 is a plan view of a strap forming means of holding the shellswith the splint according to the invention in position on each side ofthe ankle,

FIG. 6 is a side view of the strap shown in FIG. 5,

FIG. 7 is an exploded perspective view of a chamber that can bepressurised in order to form a support cushion between each shell andthe ankle,

FIG. 8 is a top view of the base of the ankle splint according to theinvention,

FIG. 9 is a sectional view along the IX-IX′ axis of a variant embodimentof the outer shell of the splint according to the invention shown onFIG. 2,

FIG. 10 is a sectional view along the X-X′ axis of the variantembodiment of the shell of the splint according to the invention shownin FIG. 9.

In this non-limitative example, we will describe an ankle splintaccording to the invention adapted for the left ankle of a person.

The ankle splint is shown vertically on FIG. 1, and is composed of tworigid and globally concave shells, a first so-called inner shell 1 thatcan be positioned on the inner side of the ankle and a second so-calledouter shell 2 that can be positioned on the outer side of the saidankle.

Each inner and outer shell 1 and 2 comprises chambers 3 and 4 on each oftheir corresponding inner walls, in other words their concave parts thatface the ankle when the splint is positioned around the ankle, thechambers being made of a flexible plastic material that can bepressurised by any appropriate means, for example a pipette, placed onthe inner wall of each shell 1 to 2 to provide a support cushion betweeneach shell and the ankle. The splint also comprises a base 5 on whichthe heel applies pressure and means 6 of holding the said shells 1 and 2in position on each side of the ankle, the base 5 and means 6 will bedescribed more precisely later on.

With reference to FIGS. 1 and 2, the outer shall 2 comprises flexibleareas 7 and 8 along its longitudinal edges, in order to avoid an injuryto the oedematous tissue subsequent to a severe or minor sprain of theankle, the flexible areas 7 and 8 applying lower pressure on theoedematous tissue during bending of the foot, which facilitates fastresorption of the oedema. Note that the central part 9 of the outershell 2 extending from its lower end to its upper end is rigid; in thiscontext, the thickness of the central part of the outer shell ispreferably greater than the thickness of the flexible areas 7 and 8 ofthe said outer shell 2. Accessorily, the central part of the outer shell2 comprises a globally circular flexible area 10 corresponding to anarea of the said outer shell that applies pressure on the medialmalleolus of the ankle that forms a protuberance from this joint. Theflexible areas 7, 8 or 10 are made partly of a flexible material,preferably SEBS, in other words styrene ethylene butylene styrene blockcopolymer (thermoplastic elastomer) mixed with a rigid syntheticmaterial such as polypropylene copolymer (PPc) or polyamide 6 (PA 6),from which the rigid part of the outer shell 2 is made.

According to one variant embodiment of the ankle splint according to theinvention and with reference to FIG. 10, the flexible areas 7, 8 or 10are made by adding a synthetic material for example such as PPc or PA6,as a hot liquid that solidifies as it cools in a mould defining theshape of the shell so as to obtain the rigid central part 9, and then byadding a flexible material, for example such as SEBS, into the saidmould in the part of the mould corresponding to the inner part of theshell such that the flexible material extends on each side of the rigidcentral part 9 to form flexible areas 7 and 8 on the inner wall of thesaid shell. Note that SEBS is a material with a particularly pleasantfeel and it improves the feeling of comfort, for example for a userwearing the splint barefoot.

Furthermore, with reference to FIGS. 1 and 2, the outer shell 2comprises a scalloped recess 11 along its front side edge, in otherwords the vertical side edge at the right of FIGS. 1 and 2 and close toits lower edge, to prevent any pressure from the side edge in contactwith the bump and on the top of the foot during bending of the leg.

With reference to FIGS. 1 and 3, in the same way as above, the innershell 1 comprises a flexible area 12 and 13 delimited by dashed lines,along its longitudinal edges. The central part 14 of the inner shell isrigid and in this respect is thicker than the flexible areas.Accessorily, the inner shell 1 comprises a flexible area 15 in its rigidcentral part 14 corresponding to the area in which the inner shell 1applies pressure on the medial malleolus of the ankle.

With references to FIGS. 1, 4 and 7, chambers 3 and 4 are solidarised tothe inner walls of the inner shell 1 and outer shell 2 by anyappropriate means such as glue or Velcro (registered trademark) typefastening means such that it covers the inner wall of each of the shells1 and 2 so as to provide a support cushion between each shell 1 and 2and the ankle. The chambers 3 and 4 have a globally triangular shape andinclude valves 16 and 17 respectively and can cooperate with anyappropriate means, such as a pipette consisting of a flexible tube, soas to pressurise the said chambers 3 and 4, the pressure being appliedby blowing into the pipette inserted in valve 16 or 17 of the chamber 3or 4. In a particularly advantageous manner, each chamber 3 or 4comprises a porous compressible element 18 placed on the inside of eachof the chambers 3 and 4, practically filling the inner volume of each ofthe said chambers 3 and 4 when these chambers are not pressurised. Theporous compressible element 18 is preferably composed of foam with slowresilience, for example such as low strength polyether foam 1.50 LR3marketed by the TRAMICO company. A low resilience polyether foam is afoam that is deformed under the effect of pressure and returns veryslowly to its initial position.

With reference to FIG. 7, the chambers 3 and 4 are obtained bythermo-welding two globally triangular sheets 19 and 20 made from aflexible plastic material such as ethyl vinyl acetylene (E.V.A.), andpreferably polyurethane, thermo-welded along their edges, the porouscompressible element 18 being positioned between the two sheets 19 and20 before they are thermo-welded.

With reference to FIGS. 1 and 4, the means 6 of holding the inner shell1 and outer shell 2 in position on each side of the ankle are composedof two velvet finish fabric straps 21, 22, a free end of which issolidarised to the outer wall of the inner shell 1 of the splint by anattachment means, for example such as a rivet 23. Each strap 21, 22comprises male attachment means 24 solidarised to the outer face ofstraps 21, 22 close to the fixed edge of the inner shell, as shown inFIGS. 1, 4, 5 and 6, the said male attachment means 24 being capable ofcooperating with the thin loops on the inner face of the velvet finishfabric straps 21, 22. A velvet finish fabric means a fabric with twosuperposed warps, one of which forms the bottom of the fabric and theother the velvet finish by thin loops on its faces. Furthermore, theloops of the velvet finish fabric of the straps 21, 22 can cooperatewith the male attachment means 25 fixed to the outer wall of the secondouter shell 2.

With reference to FIGS. 1, 2 and 4, the male attachment means 25 fixedto the outer wall of the outer shell 2 of the splint and capable ofcooperating with the thin loops of the strap 21, 22 are positioned inthe corresponding two recesses 26 formed on the outer wall of the outershell 2 such that the attachment means 25 are flush with the surface ofthe said outer wall, the said male attachment means 25 advantageouslybeing glued to the bottom of the recesses 26.

Furthermore, the male attachment means consist of hooks and the femaleattachment means consist of loops, the said hooks being capable ofcooperating with the loops and vice versa to form a Velcro (registeredtrademark) type attachment.

As shown in FIGS. 2 and 9, and according to one particularlyadvantageous execution of the splint according to the invention, themale attachment means 25 are replaced by two globally rectangulartransverse grooves 27, shown in chain dotted lines in FIG. 2, with astraight section, extending perpendicular to the longitudinal edges ofthe outer shell 2 in the central part 9 of the said shell 2 and forwhich the bottom 28 has a rough surface. Thus, the grooves 27 that holdthe fabric straps 21, 22 in position and that cannot slide along thelongitudinal centreline of the outer shell 2 and the rough surface ofthe bottoms 28 of the said grooves 27 prevent any transverse sliding ofthe straps 21, 22, by cooperating with the thin loops of the saidstraps.

It is quite obvious that the rough surface can be made from anyanti-slip material or similar material obtained either when moulding theshell 2, or by gluing the said material on the bottoms 28 of the grooves27.

With reference to FIGS. 1 to 4, each shell 1, 2 comprises two globallyrectangular parallel horizontal slots 29 and 30 at its lower end, one 30placed above the other 29, into which the fabric tabs 31 and 32extending on each side of the base 5 and that can be positioned underthe heel can be inserted. Each tab 31, 32 is inserted passing under ashell 1, 2, by inserting its free end in the first lower slot 29 fromthe outside towards the inside of the shell 1, 2, and then by insertingthe said end into the second upper slot 30 from the inside towards theoutside of the said shell 1, 2, before solidarising its free end on theouter wall of the shell 1, 2 immediately above the slots 29, 30. In thisparticular example embodiment, the first tab 31 is made of a velvetyfabric and it comprises thin loops 33 on its inner face, in other wordsthe face in contact with the outer wall of the shells 1, 2, capable ofcooperating with male attachment means 34 placed on the outer wall ofthe outer shell 2 just above the slots 29, 30. The said male attachmentmeans 34 are advantageously positioned in a recess 35 formed on theouter wall of the shell 2 such that the male attachment means 34 areflush with the surface of the said outer wall.

The free end of the second tab 32 is fixed to the outer wall of theinner shell 1 by a rivet 36.

It is obvious that the second tab 32 may also comprise thin loops on itsinner face that can cooperate with male attachment means advantageouslyplaced in a hollow formed on the outer wall of the inner shellimmediately above the slots 29, 30.

Accessorily, it is observed that the part of the shells 1 and 2extending between the slots 29 and 30 is slightly set back such that thetabs 31 and 32 extending between the said slots 29 and 30 on the innerface of the shells 1 and 2 are flush with the inner wall of the saidshells thus preventing any extra thickness that would hinder the user.

Furthermore, with reference to FIGS. 1 and 8, the base 5 is generally inthe shape of a foot and it comprises a stylised representation 37 of aleft foot on the upper face of the base 5, in other words the face ofthe base 5 facing the heel, such that the user can easily identify whichsplint he should place on his left ankle.

It is quite obvious that the base 5 of the splint corresponding to theright ankle will be marked with a stylised representation of a rightfoot on its upper face.

Accessorily, with reference to FIG. 4, the splint advantageouslycomprises a velvety fabric “strapping” 38 comprising male attachmentmeans 39 and 40 on one of its faces, placed at the corresponding freeends of the said “strapping” 38, and capable of cooperating with thethin velvety fabric loops on the outer face of the tab 34 and the outerface of the strap 22 or 21, the strapping 38 being wound around theshells 1, 2 from their lower ends as far as means 6 to hold the shells1, 2 in position on each side of the ankle. It will be observed that theterm “strapping” means application of a retaining strap around a memberof the body. This strapping 38 pulls the foot inwards while walking, tocounteract the tendency of the foot to pivot outwards due to theflaccidity of the ankle tendons caused by the severe sprain.

Finally, it is obvious that the ankle splint according to the inventioncan be adapted to all joints of a human or animal body, for example suchas the knee, elbow or wrist, that such splints only comprise a singleshell, and that the examples that have just been described are simplyparticular illustrations and in no way limit the fields of applicationof the invention.

1. A splint for a joint between two members of a human or animal body,composed of at least one rigid and globally concave shell (1, 2) thatcan be positioned around the joint, resting on the joint, wherein theconcave shell comprises a chamber (3, 4) made of a flexible plasticmaterial that can be pressurised by any appropriate means, on a concaveinner face of the at least one concave shell, wherein the chamber isplaced on the concave inner face of the concave shell (1, 2) to supply asupporting cushion between the concave shell (1, 2) and the joint, andthe chamber covers at least a part of the concave inner face of theconcave shell (1, 2); and means (6) of holding the at least one concaveshell (1, 2) in position around the joint, wherein the at least oneconcave shell (1, 2) is composed of a single element comprising a rigidpart and at least one flexible area (7, 8; 12, 13) to avoid any injuryto the oedematous tissue that developed subsequent to a severe or minorsprain of the joint, wherein the flexible area is made from a styreneethylene butylene styrene (SEBS) block copolymer mixed with a rigidsynthetic material from which the rigid part is made so that the shellis made from a single mould wherein the flexible area is chemicallybonded to the rigid part of the shell (1, 2).
 2. The splint according toclaim 1, wherein the rigid part of the at least one concave shell (1, 2)is obtained from polypropylene copolymer (PPc).
 3. The splint accordingto claim 1, wherein the rigid part of the at least one concave shell (1,2) is obtained from polyamide 6 (PA 6).
 4. The splint according to claim1, wherein the at least one concave shell (1, 2) is rigid at a centralpart (9, 14) and flexible (7, 8; 12, 13) along each of the longitudinaledges of the at least one concave shell.
 5. The splint according toclaim 1, wherein the at least one concave shell (1, 2) comprises at acentral part (9, 14) a flexible area (10, 15) corresponding to an areaof the at least one concave shell (1, 2) that rests on a protuberance ofthe joint.
 6. The splint according to claim 1, further comprised of aporous compressible element (18) placed on the inside of each chamber(3,4), filling the inner volume of each of the chambers (3,4) when thesechambers are not pressurized.
 7. The splint according to claim 6,wherein the porous compressible element (18) is composed of a foam witha slow resilience.
 8. The splint according to claim 1, wherein the means(6) of holding the at least one concave shell in position around thejoint is comprised of at least two velvet finish fabric straps (21, 22)formed from a fabric comprising thin loops on the faces of the fabric,wherein each of the velvet finish fabric straps (21, 22) having firstlya free end solidarised to the outer face of the concave shell (1, 2) ofthe splint by an attachment means the fabric straps (21, 22) beingcapable of cooperating with a first male attachment means (25) fixed tothe outer face of the concave shell(1, 2) and secondly having a secondmale attachment means (24) positioned on the outer face of the strap(21, 22) at a fixed end of the at least one concave shell (1, 2) andcapable of cooperating with the thin loops of the inner face of thevelvet finish fabric straps(21, 22).
 9. The splint according to claim 8,wherein the first male attachment means (25) consists of at least twoglobally rectangular transverse grooves(27) with a straight section,extending perpendicular to the longitudinal edges of the concave shells(1, 2) in the central part (9, 14) of the at least one concave shells(1, 2) and for which a bottom (28) of the at least one concave shell hasa rough surface.
 10. The splint according to claim 8, wherein the firstmale attachment means (25) are positioned in a recess (26) formed on theouter wall of the at least one concave shell (1, 2) such that the firstmale attachment means (25) are flush with the surface of the outer wall.11. The splint according to claim 10, wherein the first male attachmentmeans (25) of the outer face of the concave shell (1, 2) of the splintare glued to the bottom of the recesses (26) formed on the outer wall ofthe at least one concave shell (1, 2).
 12. The splint according to claim8, wherein the first and second male attachment means (24, 25) consistsof hooks capable of cooperating with the thin loops of the velvet finishfabric straps (21, 22).
 13. The splint of claim 1, wherein comprising atleast two concave shells (1, 2) capable of being positioned on each sideof an ankle.
 14. The splint according to claim 13, wherein each concaveshell (1, 2) comprises two globally rectangular horizontal slots (29,30) at a lower end of the concave shells, one globally (30) placed abovethe other globally rectangular horizontal slots (29), and into which thevelvet finish fabric tabs (31, 32) extend on each side of a base (5) andcan be positioned under a heel, each velvet finish fabric tab (31, 32)inserted such that each velvet finish fabric tab passes under one of theconcave shells (1, 2) by inserting a free end in the lower globallyrectangular parallel horizontal slot (29) from the outside towards theinside of the concave shell (1, 2), and then by inserting the free endinto the upper globally rectangular horizontal slot (30) from the insidetowards the outside of the concave shell (1, 2), before solidarising itsfree end on the outer wall of the concave shell immediately above theglobally rectangular parallel horizontal slots (29, 30).
 15. The splintaccording to claim 14, wherein the free end of at least one velvetfinish fabric tab (31, 32) comprises thin loops (33) capable ofcooperating with a third male attachment means (34) placed on the outerwall of the concave shells (1, 2) just above the globally rectangularparallel horizontal slots (29, 30), on its inner face, such that theinner face is in contact with the outer wall of the concave shells (1,2).
 16. The splint according to claim 15, wherein the third maleattachment means (34) is positioned in a recess (35) formed on the outerwall of the concave shells (1, 2) such that the third male attachmentmeans (34) is flush with the surface of the outer wall.
 17. The splintaccording to claim 14, wherein the base (5) is generally in the shape ofa foot.
 18. The splint according to claim 14, further comprising astylised representation (37) of a foot on the upper face of the basefacing the heel.
 19. The splint according claim 14, wherein the free endof one of the velvet finish fabric tabs (31, 32) are fixed to the outerwall of the concave shell (1, 2) by means of a rivet (36).
 20. Thesplint according to claim 14, further comprising a velvety fabric“strapping” (38) comprising a fourth male attachment means (39, 40) onone of the velvety fabric strapping faces, placed at the correspondingfree ends of the velvety fabric “strapping” (38), and capable ofcooperating with the thin velvety fabric loops on the outer face of thetab (34) and the outer face of the strap the velvety fabric “strapping”(38) being wound around the concave shells (1, 2) from their lower endsas far as the means of holding the concave shells (1, 2) in position oneach side of the ankle.
 21. A method for manufacturing shells (1, 2) ofa splint for a joint between two members of a human body composed of atleast two rigid and globally concave shells (1, 2) that can bepositioned on each side of the joint and can apply pressure on the jointcomprising: inserting a hot liquid synthetic material that solidifies asit cools in a mould defining the shape of the concave shells (1, 2)wherein the solidified structure defines a rigid part; and inserting aflexible material into the said mould in at least one area of the mouldsuch that a flexible part is formed and chemically bonded to the rigidpart of the concave shells.
 22. The method for manufacturing shells inthe splint for the joint according to claim 21, wherein the flexiblematerial is inserted into the synthetic material.